Patent Literature 1 describes a power conversion apparatus in which a load wire connecting an inverter and a motor passes through the core; and a grounding wire for grounding the housing of the motor also passes through the core and is connected to a capacitor on the input side of the inverter. Consequently, according to Patent Literature 1, the resonance frequency of the resonance path in the inverter is reduced due to the impedance of the core; and a damping effect is obtained for the resonance path.
Patent Literature 2 describes a power conversion system in which a power line for connecting an inverter to a motor passes through the core of a PG coil; a common mode current reflux line, functioning as a path along which a common mode current flows back, passes through the core of the PG coil; and the power line and the common mode current reflux line arranged adjacent to each other. According to Patent Literature 2, the above means the direction of the common mode current flowing through the power line and the direction of the common mode current flowing through the common mode current reflux line are opposite. Therefore, the magnetic field generated by the common mode current flowing through the power line and the magnetic field generated by the common mode current flowing through the common mode current reflex line cancel each other out, and thus noise radiated from the power line can be reduced.
Patent Literature 3 describes a power conversion system in which a filter is provided between the power conversion apparatus; the load and a power line for connecting the power conversion apparatus to the load is simultaneously wound once around a first magnetic core and a second magnetic core; and a grounding wire, connecting the power conversion apparatus housing to the housing of the load, is wound once around the second magnetic core. Further, the winding direction of the grounding wire is set such that the magnetic field generated by the electric current in the power line and the magnetic field generated by the electric current in the grounding wire cancel each other. Thus, according to Patent Literature 3, a large current flows to the filter and a power line having a large sectional area can be wound in one winding process, which enables the manufacturing process and the size of the filter to be reduced.